Recent developments in manufacturing have been directed to robots, manipulators or machines that are designed to operate with closed-loop mechanisms, such as parallel mechanisms. Parallel mechanisms incorporate several independent kinematic chains that include an assemblage of links and joints interconnected such that the links are substantially free from bending moments.
Parallel kinematic machines, i.e. machines that are based on parallel mechanisms, and parallel robots are capable of operating at high speed and acceleration, and combine high rigidity with high flexibility and accuracy. Prior art parallel robots include a traveling plate or mobile platform that can operate with many degrees of freedom, but also require an equivalent number of costly actuators.
U. S. Pat. Nos. 5,333,514 and 5,857,815, for example, disclose parallel robots or manipulators with six degrees of freedom. European Patent Application EP 1 084 802 A2 discloses a parallel robot with four degrees of freedom. U.S. Pat. No. 6,161,992 discloses a machining system with a parallel mechanism having three degrees of freedom.
One embodiment of the invention provides an apparatus comprising a frame, a mobile platform and first and second linearly-actuated slides supported on a base connected to the frame. The first and second slides are movable along a line defining a first axis. The apparatus may include a first driving connector movably coupled to the first slide and to the mobile platform, and a second driving connector movably coupled to the second slide and to the mobile platform, such that the mobile platform is displaceable within at least two degrees of freedom defined by linear motions along the first axis and a second axis, the second axis being coplanar and orthogonal to the first axis. An end effector may be also coupled to the mobile platform, the end effector having an axis aligned in a direction defined by the second axis. The end effector may comprise, for example, a tool or a gripper.